1. Field of the Invention
This invention relates to a method and apparatus for imparting continuous passive motion to a human joint.
2. Description of the Prior Art
"Continuous Passive Motion" (CPM) is the concept--both biological and clinical--of applying slow, rhythmic and continuous movement to joints immediately following joint injury or surgery. This concept is described, more fully, in the brochure "What is Continuous Passive Motion?" published by Toronto Medical Corp., Scarborough, Canada, incorporated herein by reference.
An apparatus for imparting continuous passive motion to joints is disclosed in U.S. patent application Ser. No. 362,896, filed Mar. 29, 1982, now U.S. Pat. No. 4,487,199, Dec. 11, 1984. Specific embodiments of that apparatus, originally developed for pediatric and sports medicine, have been put into commercial practice and are ideal under certain circumstances.
This earlier apparatus has some shortcomings, particularly as applied to heavier patients and older patients. Insufficient support is provided for the leg, the load on the foot is too great and there was no lifting motion for the knee.
An aim of the present invention is to provide an apparatus which avoids the shortcomings of the earlier apparatus and provides certain positive advantages as will be described, particularly for mobilizing the hip, knee and ankle joints.